1997 GMC Safari Multiple O2 Sensor Codes P0134, P0135, P0146, P0147, P0300 - What to Do?
I own a 1997 GMC Safari that runs smoothly and has recently had spark plugs, wires, cap, and rotor replaced at 100,000 miles. During an emissions inspection, I received several diagnostic trouble codes: P0134, P0135, P0146, P0147, and P0300. Most of these codes are related to oxygen (O2) sensors. Should I replace all three O2 sensors? Could the P0300 multiple cylinder misfire be caused by faulty O2 sensor readings or wiring issues? Any advice on troubleshooting this problem would be greatly appreciated.
How many miles has your vehicle accumulated? Please check the wiring and electrical connections to each oxygen sensor, as loose or corroded connectors can trigger these codes. Also verify that the relevant fuses are intact. Good luck—please update us on your findings and any progress made.